The present invention is generally related to methods and apparatus for comminuting biological specimens onsite or in a laboratory, and is more particularly related to devices used for providing biological specimens for subsequent chemical analysis.
For the purposes of this application, the term “comminution” will be understood to mean to mechanically reduce to powder, pulverize, grind, shred, tear or otherwise increase the surface area of biological specimens including, but not limited to hair, feathers, nails, hooves, claws, horns, fur, beaks, scales and other sources of keratin, (or access to the cortex of the specimen), as well as bone, tissue, organs and/or muscle found in humans and animals (hereinafter referred to as biological specimens or samples), whether or not in the presence of a carrier liquid, so that the specimen is readily subject to extraction or detection of drugs and their metabolites, compounds, chemicals or other pharmacologic agents.
Increased drug abuse in North America has been associated with criminal activities, health problems, newborn addiction, lost worker productivity and staggeringly high medical costs. Currently of greatest concern are opiates (heroin, morphine, codeine), cocaine, marijuana, MDMA (Ecstasy), phencyclidine, amphetamine and methamphetamine.
Possible pesticide residues in the breast tissues of women and the concern over the presence of synthetic agents and compounds in plant and animal foodstuffs has raised concerns about possible environmental exposure including air- and water-borne agents, as well as, exposure of domestic animals to agricultural chemical agents such as pesticides and herbicides, growth hormones and/or antibiotics. Verifying a natural “organic” status prior to slaughter has, thus, recently become of significant interest.
In testing for human drugs of abuse, several test systems are presently marketed for detecting drug analytes in urine e.g., ONTRAK™ and ONLINE™ (Roche Diagnostic Systems, Inc.), the ADx™ automated fluorescence polarization immunoassay system (Abbott Laboratories, Inc.) and EZ-SCREEN™ (Environmental Diagnostics). Unfortunately, there are significant problems associated with urine testing for drugs of abuse, e.g., (i) possible false positive results for opiates recorded in subjects who are on certain medications and who have recently ingested poppy seeds; (ii) rapid elimination rates and short half-life of many drug metabolite compounds; and particularly (iii) false negatives associated with purposeful adulteration, dilution, urine substitution and other creative ways donors discover to beat a drug test.
Unlike liquid urine samples, solid samples such as hair require special sample preparation prior to conducting assays. Conceptually, hair provides a better toxicological specimen than urine, serum, sweat or saliva because its relatively slow growth increases the period of time during which drug usage is detectable. Human head hair grows approximately 1/64 (0.016) inch per day, thus creating a calendar of drug use. It takes about seven (7) days after ingestion of drugs for the drugs to be extractable from hair outside the scalp. Approximately 1.5 inches of human head hair can show drug usage over a ninety (90) day period. The hair can also be sectioned into periods of thirty (30) day use.
In present day practice, extraction of drugs from hair often involves cutting the hair it into small pieces using razor blades or scissors and inserting the cut hair into a test tube where it is then exposed to acid and/or base hydrolysis, prolonged enzymatic digestion, heat, organic solvent extraction and/or sonication. The cutting procedure is labor intensive, time consuming and is subject to the particular cutting techniques of individual technicians. Also, when multiple specimens need to be analyzed, technicians are subject to repetitive stress injuries. These methods require technical experience and are presently most easily conducted in a test laboratory. However, even then the sample process can take two to three hours to complete, and the results are not available for as long as seven days, the samples frequently suffer from poor reproducibility, there are long delays before results can be released and, even then, variability occurs in the ability to isolate different drugs and their metabolites. Hydrolysis conditions can also result in conversion of drug metabolites such as 6-monoacetylmorphine, i.e., whose presence provides judicial proof of drug abuse, into parent compounds, i.e., morphine. Fortunately, it has been found that certain drugs and their metabolites can persist in hair for extended periods of time.
Another method for preparing a sample of hair for chemical analysis is for a technician to freeze dry the sample using liquid Nitrogen, then grind the frozen hair in a mortar and pestle for 5 to 10 minutes until it is powdery in appearance. This comminution or maceration operation is useful for increasing the surface area of the hair and, thus reducing the reaction time of the analytical chemicals on the sample and increasing extractability of the agents of interest. Using this method the amount of prepared specimen obtained for analysis may vary by sample as well as by individual technician, and the liquid Nitrogen limits usage to a laboratory setting. An alternative procedure for comminution involves a ball mill, but that device inherently has contamination issues with the balls from sample to sample, and is thus only useful in a laboratory process and this method of comminution is relatively slow.
There is a need for a rapid mechanical comminution method and apparatus for biological specimens which method is easily adapted to both portable on-site comminution and laboratory comminution to prepare samples for detection of the agents of interest. There is also a need for a comminution method and apparatus for such specimens which is repeatable on an objective basis, maximizes sample integrity by eliminating cross contamination between specimens, increases the surface area of the hair and exposes the cortex of the hair for increased and rapid extractability of the agents of interest.